Though who in this whole game is important enough to come after Mithala? I'd say only the priests.
... except if Eleven isn't Mithala, it must have
preceded him, because he would then have to be Twelve.
EDIT: I'd say it has to be Mithala, because there's just no one else for it to be--perhaps he made them and left them, and over the following centuries they reimagined him in their own image? Except
Mithala made all of the Mithalans instead of the Creator, so I wouldn't expect any of them to be Twelve; otherwise the Druniads, the Forest Sprites, and Naija would be on that wall. So... yeah.
EDIT EDIT EDIT: It occurs to me that there's a great big crownéd skeleton in the Bone Cave that's otherwise unaccounted for. I suppose he could have been an extremely large Mithalan king from ages long past, but that doesn't really feel right.